EP 3794842 A1 20210324 - OPTICAL MICROPHONE ASSEMBLY
Title (en)
OPTICAL MICROPHONE ASSEMBLY
Title (de)
OPTISCHE MIKROFONANORDNUNG
Title (fr)
ENSEMBLE MICROPHONE OPTIQUE
Publication
Application
Priority
- GB 201807889 A 20180515
- GB 2019051323 W 20190515
Abstract (en)
[origin: WO2019220103A1] An optical microphone assembly (38) comprises a rigid substrate (42); an interferometic arrangement, a light source (48), at least one photo detector (50) and an enclosure (74). The interferometric arrangement comprises a membrane (46) and at least one optical element (62) spaced from the membrane (46), wherein the at least one optical element comprises a surface (60) of the substrate (42) and/or is disposed on a surface (60) of the substrate (42). The light source (48) is arranged to provide light to the interferometric arrangement such that a first portion of the light propagates along a first optical path via the interferometric arrangement and a second portion of the light propagates along a second different optical path via the interferometric arrangement, thereby giving rise to an optical path difference between the first and second optical paths which depends on a distance between the membrane (46) and the optical element (62). The photo detector(s) (50) are arranged to detect at least part of an interference pattern generated by said first and second portions of light dependent on said optical path difference. The enclosure (74) is arranged to form an acoustic cavity (76) in fluid communication with one side of the membrane (46). The volume of the acoustic cavity (76) is at least 3mm multiplied by d2, where d is a diameter of the membrane (46).
IPC 8 full level
H04R 23/00 (2006.01)
CPC (source: EP KR US)
G01B 9/02051 (2013.01 - US); H04R 23/008 (2013.01 - EP KR US); H04R 2201/003 (2013.01 - EP KR US)
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
WO 2019220103 A1 20191121; CN 112470493 A 20210309; CN 112470493 B 20221216; EP 3794842 A1 20210324; GB 201807889 D0 20180627; JP 2021524685 A 20210913; JP 7387645 B2 20231128; KR 20210020910 A 20210224; US 11240607 B2 20220201; US 2021274291 A1 20210902
DOCDB simple family (application)
GB 2019051323 W 20190515; CN 201980032198 A 20190515; EP 19726472 A 20190515; GB 201807889 A 20180515; JP 2020564489 A 20190515; KR 20207036021 A 20190515; US 201917054981 A 20190515